In cold winter climates in the wintertime, there is a significant problem of ice build-up of the roofs of heated buildings, and particularly houses. Houses are typically constructed with the edge portions of the pitched roof extending beyond the main frame of the house. The major portion of the roof of the house located above the main frame receives some heat due to heat rising up from the warm house interior. This heat, alone or in combination with heat from the sun, can cause melting of snow and ice located over the major portion of the roof that covers the main frame of the house. The extended minor roof portion is not directly over the main house frame and thus is not heated to the same extent as the major roof portion. Water from melted ice or snow on the major roof portion running off the roof has a propensity to refreeze when it reaches this colder, extended portion of the roof. Gradually, a blockage of ice can build up at the edge of the roof. This ice blockage prevents further flow of water from melted snow and ice from the major roof portion. When this additional flow reaches the ice blockage it is stopped and caused to back up, oftentimes backing up underneath the roof shingles and causing damage. Not only can damage to the roof result, but water may enter the interior of the house and damage the walls and ceilings thereof.
Various devices have been proposed to melt a portion of this ice blockage on the roof and permit water flowage. For example, see the devices of U.S. Pat. No. 3,141,955 issued July 21, 1974, to Culpepper and U.S. Pat. No. 3,725,638 issued Apr. 3, 1973, to Solin et al. Also, there are available devices known as heat tapes or cables which are laid along the roof edge and the electrically heated to attempt to prevent such ice blockage. Operation of these devices is expensive, and sometimes prohibitively so, due to the amount of electricity consumed in generating the heat. The majority of heat generated by such devices is lost to the surrounding atmosphere. Relatively little of the heat is used for the desirable purpose of melting the ice.